Electric-arc lamp



(No Model.)

B. THOMSON.

ELEUTRIG ARC LAMP. No. 297,197. Patented Apr. 22, 1884.

- MTI 1191,

I llllllll umllll UL! Minn i a o I v UNTTED STATES AIENI Tires.

ELIHU THOMSON, OF LYNN, MASSACHUSETTS, ASSIGNOR TO THE THOMSON- HOUSTON ELECTRIC COMPANY, OF CONNECTICUT.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 297,197, dated April 22, 1884.

Application filed January 5, 1884. (No model.)

To ctZZ whom it may concern.-

Be it known that I, ELIHU THoMsoN, a citizen of the United States, and a resident of Lynn, in the county of Essex and State of Massachusetts, have invented certain new and useful Improvements in Electric-Arc Lamps, of which the following is a specification.

The object of my invention is generally to improve and simplify the construction and op- 1 1o eration of electric-arc lamps.

' My invention relates more especially to electric-arc lamps of such construction that the control of the carbons is effected by the action only of a derived-circuit magnet of high re- I 5 sistance acting in opposition to a suitable retractor. 7

My invention consists in providing a resistan ce in a branch around the carbons, and preferably of an amount greater than the arc, the

function of which resistance is, at starting of the lamp, to force an abnormal amount of current into the high-resistance derived circuit, which abnormal current is effective in bringing the feed-regulating mechanism into normal or proper position for producing a feedof the carbon. Immediately thereafter the resistance branch is broken automatically, either by the movement of the feed-regulating mechanism or supporting-lever therefor, or by the 0 actual establishment of the circuit through the carbons, and is kept broken so long asthe lamp is in action. When the lamp ceases to act or the current ceases to How, the resistance branch is established, either automatically or by hand,

3 5 ready for the next operation. The device for breaking the resistance branch may be a circuit controller or switch of any desired construction, and is so constructed or arranged as to maintain the circuit of the branch while the feed-regulating mechanism is moving from its extreme retracted position to a normal or carbon-releasing position, or until the circuit is established in the carbons, when it is automatically released, either by mechanical or electrical means, and opens thebranch, so'as to leave the circuits of the lamp in their ordinary condition, and to thus permit the regulation or control of the carbons to proceed by the action of the current in the ordinary high-re- -.5o sistance derived circuit acting in opposition i to a-suitable spring or other retractor.

. In carrying out my invention I may use any form or construction of regulating mechanism.

In the present case I have shown and described a clutch or clamp; but I do not limit myself to such device, and may employ a gear-train or other mechanism: The magnet system and controlling-lever are so arranged or combined that when the retractor of the controlling-lever prevails over the effects of the current in the regulating derived circuit the carbons will be raised or separated, while if the magnet or other device in the derived circuit prevails the regulating mechanism will be moved against the influence of the retractor and a feed of the carbon permitted. WVhen the arc is normal, the forces are balanced and the mechanism is at rest.

My invention provides a means of bringing the lamp into action by causing at the start an abnormal or increased flow of current in the high-resistance derived circuit, so that the lamp mechanism may be brought into proper position for starting the lamp or permitting the carbons to come together. Such abnormal flow is caused by the resistance branch around the carbons at the start, and is lessened or restored to normal amount by the breaking of the branch. When this occurs, the retractor for the regulating mechanism acts and sepa- 8o rates the carbons, so as to form the arc, and the operation then goes on under the joint control of said retractor and of the current forced into the regulating high-resistance derived circuit by the arc resistance. The means in such high-resistance derived circuit for starting the lamp is preferably the regulating-magnet; but I do not limit myself in this respect, since the gist of the invention consists in starting the lamp by the abnormal flow of current in said circuit produced by the resistance around the carbons at starting.

Some of the many ways in which my invention may be carried into effect are shown in the accompanying drawings, in Which Figure 1 is an elevation of a lamp embodying my invention. Fig. 2 illustrates a modification. Fig. 3 shows another form of circuit controller or switch that may be used for breaking the starting resistance branch automatically. Fig. 4 shows the form of feed-regulating magnet which I prefer to employ.

Referring to Fig. i, It indicates the ordinary tion of the i'cedq'egulating mechanism in such carbon-holder for the upper or positive carbon of an electric-arc lamp, and E E, respectively, the positive and negative carbons.

L indicates a feed-regulating lever, pivoted at p and acted upon by the opposing influences of a retractor, S, and of current iiowing in a higlrresistance derived circuit around the carbons. Theintluence of such cu rrent is brought to bear in the present case, in the ordinary way, by means of a high-resistance magnet, K, whose coils are in the ordinary highresistance shunt around the carbons indicated by the numeral 5, which magnet acts upon a core or armature connected to L.

l is the pole of the magnet, and B a peri'orated ari'nature attached to L, and embracing the conoidal or paraboloidal pole P. This form is adopted in order that the magnet may exert the same pull upon the lever L in all positions ot' the armature for the same strength 01 current.

The magnet K is preferably a horseshoemagnct, as indicated in Fig. 4. It is, however, to be understood that my invention is not limited to any particular form or construction of the magnet system.

Lever L is the feed regulating or controlling lever of the lamp, and serves to adjust the position of the carbons by acting directly or in directly upon any suitable devices that will, when moving in one direction, raise the upper carbon, and when moved in the opposite direction to a certain extent will permit the carbon to feed or approach the opposite carbon. As typical of such devices, I have herein shown a clamp or clutch connected with lever L by a link, 1), so as to be raised or lowered by said lever, or held stationary, according to the relative strength of the current in the hi glircsistance-regulating circuit 5 and the strength 01' the ictractor for the lever. Any other devices may be used in place ol the clutch, provided they be of proper construction to cause a release of the carbon when moved in one direction, and to lift the carbon when moved in the opposite direction. The clutch here shown is of the form heretofore invented by me, and consisting, briefly speaking, of a clamp body or guide, 0, through which the carbon or carbon-carrier may move, a dog or toe, d, pivoted on said body, and held normally in engagement with the carbon or carrier by means of aspring, Z, applied to an arm extending from the toe, so as to prevent the carbon from moving downward through the clutch, and a stop. F, with which the arm engages to release the toe and permit the carbon to feed down whenever the clamp is lowered to a sulfieient extent by the regulating-lever or other device, L.

\V indicates the artificial or starting resistance of my invention, which is placed in a branch, 7, around the carbons at the starting of the lamp, and whose otlice is to force an ab normal current into the derived-circuit branch 5, so that the magnet K or other device in said branch may act upon the lever L or other porway as to lower the clutch or clamp into the position where it will produceal'eed olthe carbon. The resistance V is preferably greater than that of the normal arc, and its circ-uitis closed at the start through the contacts Q of a suitablc switch or circuitcoutroller, N, carrying an armature, T, for an electro-magnet, V, and provided with a retractor, S, that opens the switch when magnet V loses its power. In the arrangement here shown the contacts Q have to be closed by hand by an attendant at the moment the current begins to flow, after which they are kept closed by means of the electro-niagnct V, whose coils are in the circuit 7 with XV, and whose armature is at tached to the controller N, while the feed-regulating mechanism is being lowered by means of the lever L, under the action of the current forced into the circuit 5 and the coils of K. WVhile current flows in the carbon circuit magnet V is shunted and is powerless to hold the switch N against the force of its rctractor S.

The operation is as follows: \Vhen no current is passing, the carbons are held apart by the action of spring S, which retracts the lever L to its extreme position. NVhen the current is turned on, it finds two paths-one through 5 and coils of K, and the other through \V, magnet V, and contacts Q, which have been at the time closed by hand or other means. The resistance XV forces currents into K to an abnormal amount, and the latter pulls down the lever against the force of the retractor S, the contacts Q in the meantime remaining closed by the attraction of V. \Vhen the lever is pulled down to the proper point, the carbon E feeds down into contact with E, and thus shunts the currentfrom V, so that the spring #15 opens contacts Q, thus breaking the circuit of \V. The circuits are now in their normal relation, and the spring S acts to raise the clutch and the upper carbon until its force is balanced by the current forced into K by the lengthening are. An are of a determinate length having been thus formed, the operation of the lamp continues in the obvious and well-known manner, an increase of are resistance increasing the power of K, so that lever L will be operated and produce a feed of the carbon.

The arrangement shown in Fig. 2 provides a means cnti rely automatic in its character l'ormechanism is operated as before to permit the carbons to come together, immediately upon which the circuit through V is established and the contacts Q are opened by the action of said magnet on its armature T. Contacts Q I lamp mechanism has been brought into operare now kept open by V so long as the lamp continues to act and current flows through the carbons. WVhen the arc is extinguished, the spring S comes into play and closes contacts Q, ready for the next operation.

Instead of the magnetic arrangements described for controlling the switch, other devices may be employed.

In Fig. 3 I have shown a device that may be used for this purpose and that is purely mechanical in its operation. It is arranged to be operated by the lever L directly, or by some part moving therewith. This arrangement is made the subject of claims in another application for patent filed by me January 5, 1884, No. 116,513, and in which I have also shown other circuit-closing devices that may be employed in place of those shown in this case. In this instance contacts Q are closed by means of an insulated catch, M, on the lever L, which catch engages with lever N when L is retracted to its extreme position, owing to the withdrawal of current from the line. The circuit 7 is thus established, and when current is turned on produces, as before, an abnormal flow of current in K and a lowering of the clamp. In the forward movement of L in this operation, the catch M remains engaged with N, thus keeping the contacts Q closed until by the movement of the end of N inward on the arc of a circle the engaging parts are released, whereupon the circuit 7 is opened, and the switch N is thrown back by its retractor out of range of the catch M and the contact carried thereby in the normal or usual movement of L in controlling the position of the carbons. The disengagement of the parts and the opening of the contacts are suitably timed to take place when lever L and the feed mechanism have been lowered to such a point that the carbons may come together. A suitable stop controls the backward movement of the switch-lever N and retains it in such position that when the lever L is withdrawn to its extreme position by the action of its retractor S the catch M may again automatically engage with N, and at the same time close the starting-circuit 7, ready for the operation.

Many other modifications may be made in the form and disposition of the parts without departing from the invention.

In another application for patent filed by me January 4, 1884, N 0. 116,404, I have broadly claimed the combination, with the high-resistance magnet, of an artificial resistance around it for bringing the lamp into action; but the resistance in that case does not, as in this, form a shunt to the carbons also.

What I claim as my invention is 1. The combination, in an electric lamp, of feed mechanism, a derived-circuit magnet of high resistance regulating or controlling the same, a resistance in a branch around the car bons closed at the start, and means for throwing said resistance out of circuit when the ative position.

2. The combination, in an electric-arc lamp, of a high-resistance derived-circuit magnet, feed mechanism controlled thereby, a resistance somewhat greater than the normal arc in a branch around the carbons for forcing current into the high-resistance derived circuit to start the lamp, and a circuit-breaker for breaking the circuit of said resistance when the lamp mechanism has been brought into operative position, so as to leave the lamp to the controlling action of the derived-circuit magnet only.

3. The combination,in an electric lamp, of a high-resistance derived-circuit magnet, a retractor for the armature-lever thereof, feedregulating mechanism controlled by said lever, a resistance somewhat greater than the normal arc in a branch around the carbons, and

means for breaking said branch and keeping it broken when the current passes through the carbons, so that the lamp may continue in operation by the action of the derived-circuit magnet only.

4. The combination,in an electric lamp whose carbon circuit is broken when the lamp is out of action, of a high-resistance derived-circuit magnet, feed mechanism controlled thereby, a resistance in a branch around the carbons, and means for breaking said branch when the feed mechanism has been brought into normal or feed-regulating position, as and for the purpose described.

5. The combination,in an electriclamp, of a high resistance derived circuit containing means for regulating the position of the carbons, a carbon circuit open when the lamp is out of action, a resistance in a branch around the carbons, and a circuit-controller therefor actuated by a magnet in the carbon circuit, as and for the purpose described.

6. The combination,in an electriclamp, of a regulating-lever, L, a high-resistance or derived-circuit magnet, and a retractor acting upon said lever in opposite directions, feedregulating mechanism that holds the carbons apart when the lever is retractedto an extreme position, a resistance in a branch around the carbons, and means for breaking said branch and holding it broken when current flows through the carbons.

7. The combi nation,in an electriclamp whose carbons are separated at the start, of a highresistance derived-circuit magnet, feed mechanism controlled thereby, and a resistance in a branch around the carbons for forcing current into the high-resistance magnet, so that it may have power to start the lamp.

8. An electric lamp constructed to have three conducting-pathsone through the .carbons, one through the high-resistancc-controlling magnet, and athird through a resistance greater than that of the arc-as and for the purposes v around the carbons containing a resistance Signed at Lynn, in the county of Essex and preferably greater than the normal arc, and State of BIassachnsetts, this 1st day of Janelosed at starting of the lamp, and means for nary, A. D. 1884-. bringing the lamp mechanism into operation,

7 e r X r 5 placed in the high-resistance circuit and en- LLHIU HIOMSOL ergized by the abnormal flow of current pr0- WVitnesses: dnccd therein by the presence of the second V. O. 'WAKEFIELD, resistance branch. E. B. DOEN. 

